Police in Massachusetts say a charter bus driver failed to heed low-clearance warning signs before he struck a bridge, injuring dozens of high school students and their adult chaperones on board.

The bus, which was carrying 42 students and teachers from Philadelphia, Pennsylvania, crashed into Western Avenue Bridge on Soldier's Field Road in Boston during a return trip from a visit to Harvard University.

Thirty-five people were injured in the crash, Massachusetts state police said.

The Boston Emergency Medical Services said one person was in hospital with life-threatening injuries and three with serious injuries.

Authorities said the bus did not belong on the road, where a 10-foot (3-metre) height limit is in place and oversized vehicles are not authorised to travel.

State police said the driver will likely be cited for an over-height violation. An investigation will determine if he faces more serious charges.

Ray Talmedge, owner of the Philadelphia-based Calvary Coach Bus company, told WCAU-TV that the driver, Samuel J Jackson, looked down at his GPS and saw the bridge too late to avoid hitting it.